1. Field of the Invention
The present invention relates to semi-trailer vehicles and more particularly to methods of covering cargo on semi-trailers, such as `flat deck` trailers.
2. Description of the Related Art
Most durable goods and raw materials are shipped by semi-trailer vehicles on the public highways of the developed world. These vehicles are known to have a tractor unit and a semi-trailer unit, the trailer coming in a variety of arrangements depending on its intended cargo. The trailer, for example, may be a van type with a substantially weather proof interior cargo hold, or a flat bed or flat deck trailer. In the latter case, the cargo must be covered in some fashion to protect the cargo from the elements. Conventionally this is done by flexible tarps wrapped around the cargo and fastened in place with rope or elastic fastener materials.
Other covers for the cargo on a flat deck trailer are sold under the tradenames "ROLL BACK" or "ROLL TITE". These covers are individually installed and permanently fitted to each individual flat deck trailer. This is done by modifying the trailer by removing the `rub rail` from the periphery of the trailer. Other tarping arrangements include rack and tarp arrangements which have modified posts placed along the periphery of the flat deck trailer to position plywood sheets in an upright position. The tarp is then stretched over the cargo or, in the case of the rack and tarp arrangements, stretched over the space between the sheets to provide a measure of weather protection for the cargo.
Though tarps arrangements such as this are generally satisfactory, they do have some inherent weaknesses. For example, the tarps are relatively heavy and difficult to handle when manually stretched over the cargo. They tend to rip or simply become unfastened due to the buffeting wind forces exerted on the tarp during use. In either case, the cargo can become exposed to the elements and therefore be damaged. Tarped flat deck trailers also do not have important clearance lighting, thus increasing the risk of traffic accidents.
It is an object of the present invention to provide obviate these disadvantages.